From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: multipath - AAArgh! How do I turn "features=1 queue_if_no_path" off? Date: Thu, 01 Oct 2009 08:24:30 +0200 Message-ID: <4AC44B1E.7020509@suse.de> References: <4AC333E2.9090005@Calva.COM> <20090930154212.GA8507@us.ibm.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20090930154212.GA8507@us.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: dm-devel@redhat.com List-Id: dm-devel.ids malahal@us.ibm.com wrote: > John Hughes [john@Calva.COM] wrote: >> I want to turn queue_if_no_path off and use >> >> polling_interval 5 >> no_path_retry 5 >> >> because I've had problems with things hanging when a lun "vanishes" (I= =20 >> deleted it from my external raid box). >> >> But whatever I put in /etc/multipath.conf when I do a "multipath -l" o= r=20 >> "multipath-ll" it shows: >=20 > Did you reload the mapper table? >=20 >> 360024e80005b3add000001b64ab05c87dm-28 DELL ,MD3000 =20 >> [size=3D68G][features=3D1 queue_if_no_path][hwhandler=3D1 rdac] >> \_ round-robin 0 [prio=3D3][active] >> \_ 3:0:1:13 sdad 65:208 [active][ready] >> \_ round-robin 0 [prio=3D0][enabled] >> \_ 4:0:0:13 sdas 66:192 [active][ghost] >> Which is entirely correct. The 'queue_if_no_path' flag _has_ to be set here as we do want to retry failed paths, if only for a limited amount of retries. The in-kernel dm-multipath module should handle the situation correctly and switch off the queue_if_no_path flag (=3D pass I/O errors upwards) when the amount of retries is exhausted. You can only switch the flag off by setting 'no_path_retry failed'. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: Markus Rex, HRB 16746 (AG N=FCrnberg)